Preparation of spray on bandage

ABSTRACT

A BANDAGE IS FORMED IN SITU ON A WOUND BY SPRAYING ON SEPARATELY OR SIMULTANEOUSLY A HYDROPHILIC WATER INSOLUBLE POLYMER AND A HIGH BOILING PLASTICIZER OR SOLVENT THEREFOR. PREFERABLY THE POLYMER IS A HYDROXY LOWER ALKYL ACRYLATE OR METHACRYLATE. MEDICALLY ACTIVE INGREDIENTS CAN BE INCLUDED IN THE COMPOSITION.

1971 F. E. souu: E

PREPARATION or sun on BANDAGE Filed D60. 3, 1969 1 mvsm'oag mic/$56 0 04p wwlgyh ATTORNEYS United States Patent 3,577,516 PREPARATION OF SPRAY0N BANDAGE Francis E. Gould, Princeton, and Thomas H. Shepherd,

Hopewell, N.J., assignors to National Patent Development Corporation,New York, N.Y.

Continuation-impart of applications Ser. No. 567,856,

July 26, 1966, now Patent No. 3,520,949, Ser. No.

650,259, June 30, 1967, and Ser. No. 654,044, July 5,

1967. This application Dec. 2, 1969, Ser. No. 881,376

Int. Cl. A611 15/00 US. Cl. 424-46 17 Claims ABSTRACT OF THE DISCLOSUREA bandage is formed in situ on a wound by spraying on separately orsimultaneously a hydrophilic water insoluble polymer and a high boilingplasticizer or solvent therefor. Preferably the polymer is a hydroxylower alkyl acrylate or methacrylate. Medically active ingredients canbe included in the composition.

The present application is a continuation-in-part of application Ser.No. 567,856 filed July 26, 1966 now Pat. 3,520,949 issued July 21, 1970;application Ser. No. 650,259, filed June 30, 1967 and now abandoned; andapplication Ser. No. 654,044, filed July 5, 1967.

The present application relates to spray-on bandages.

A spray-on bandage offers a convenient, easy method of protecting minorwounds, cuts and/or abrasions during the healing process, and avoidscertain undesirable characteristics associated with the use ofsubstrates coated with pressure sensitive adhesives and gauze pads; suchas pain and peeling of hair during removal, disagreeable appearance,adhesion of the healing area to the gauze pad, etc. i

The requirements for a fully acceptable spray-on bandage include thefollowing:

(1) It protects the wound from air borne bacteria and dirt.

(2) It has moisture vapor permeability sufiicient to preventaccumulation of aqueous fluid under the bandage.

(3) It must be non-toxic and non-irritating to the skin.

(4) It should not adhere to the wound area or permit infiltration byregenerating tissue.

(5) It should not cause a burning or stinging sensation when applied.

(6) It should not be water soluble or rendered tacky by contact withwater to avoid dirt accumulation.

(7) It should be readily removeable when desired.

Prior art spray-on products suffer from a number of disadvantages withrespect to the above criteria. Thus prior art materials having thedesired moisture vapor permeability coupled with water resistance mustbe applied as a spray from alcohol or similar solvent solution whichcauses a strong burning sensation in the wound area.

It is an object of the present invention to develop a spray-on bandagehaving all seven of the above set forth desirable characteristics whileavoiding the disadvantages of prior art spray-on bandages.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter; it should be understood, however, that the detaileddescription and specific Patented May 4, 1971 example, while indicatingpreferred embodiments of the invention, are given by way of illustrationonly, since various changes and modifications within the spirit andscope of the invention will become apparent to those skilled in the artfrom this detailed description.

It has now been found that these objects can be attained and a filmforming action can be caused by applying a mixture of a powder ofcertain water insoluble, hydrophilic polymers having a high moisturevapor permeability with high boiling non-toxic polar plasticizersolvents therefore to, in effect, create a room temperature gellingplastisol which has high moisture vapor permeability, is sufficientlyadherent to the skin to remain in place for extended periods of time,and adequately protects wound areas from contamination. Films producedby this technique are readily removed by soaking the bandages area inwater for a few minutes which loosens the bond between the plastisolfilm and the skin. The film can then be readily pulled from the skinsurface without discomfort.

The invention can be used to form spray-on bandages not only for humanwounds but also is useful in the field of veterinary medicine for woundson the skins of animals such as dogs, cats, sheep, cattle (e.g. toprotect cows having mastitis on their teats), goats, pigs and horses andzoological animals such as lions, tigers, deer, zebra, etc.

Furthermore there can be incorporated in the films of the inventionmedically active ingredients which will diffuse from the film to thewound area over extended periods of time and keep the wound area freefrom infection, or provide local anesthesia or analgesia properties.

The medically active ingredients can be incorporated in the film byeither 1) having them impregnated in the polymer or (2) mixing theactive ingredient with the polymer powder, or (3) dissolving ordispersing the active ingredient in the high boilingplasticizer-solvent.

Polymer powders useful in this invention include polymers of hydroxylower alkyl acrylates and methacrylates alone or coplyrners with eachother, e.g. copolymers of 1 to 99% of each. Such polymers includehydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxy propylacrylate and hydroxypropyl methacrylates. The preferred polymers arehydroxy lower alkyl methacrylates, especially hydroxyethyl methacrylatepolymers.

There are also be used copolymers of the hydroxyalkyl acrylates andmethacrylates with up to weight percent of lower alkyl acrylates andmethacrylates, e.g. methyl acrylate, ethyl acrylate, propyl acrylate,isopropyl acrylate, butyl acrylate, methyl methacrylate, ethylmethacrylate, isopropyl methacrylate and butyl methacrylate, hydroxylower alkoxy lower alkyl acrylates and methacrylates, e.g. diethyleneglycol monoacrylate, diethylene glycol mono methacrylate, dipropyleneglycol mono acrylate, dipropylene glycol mono methacrylate, acrylamide,methacrylamide, N-methyl acrylamide, N-methyl methacrylamide, N-ethylacrylamide, Nethyl methacrylamide, N- propyl acrylamide, N-propylmethacrylamide, N-isopropyl acrylamide, N-isopropyl methacrylamide,lower alkoxy lower alkyl acrylates and methacrylates such asmethoxyethyl acrylate, methoxyethyl methacrylate, ethoxyethyl acrylateand ethoxyethyl methacrylate, amine compounds, e.g. p-aminostyrene,2-amino-4- vinyltoluene, diethylaminoethyl acrylate, diethylaminoethylmethacrylate, dimethylaminoethyl acrylate, dimethylaminoethylmethacrylate, t-butylaminoethyl methacrylate, piperidinoethyl acrylate,2-vinyl pyridine, dimethylaminopropyl methacrylate, diacetoneacrylamide, diacetone methacrylamide, N- vinyl pyrrolidone.

The copolymerizable material should not be used in such amount as toreduce the compatibility of the hydroxyalkyl acrylate or methacrylatewith the solvent or plasticizer or render it either too soluble in wateror reduce its hydrophilic properties too greatly.

Usually the hydroxyalkyl acrylate or methacrylate is at least 80% byweight of the total monomers.

Useful, but less preferable, copolymers are prepared from lower alkylacrylates and methacrylates, e.g. having 1 to 3 carbon atoms in thealkyl group such as methyl acrylate, ethyl acrylate, isopropyl acrylate,methyl methacrylate, ethyl methacrylate and propyl methacrylate with3080% of ethoxyethyl acrylate, methoxyethyl acrylate, methoxyethylmethacrylate, ethoxyethyl methacrylate, acrylamide, methacrylamide,n-alkyl substituted acrylamides and methacrylamides such as N-methylacrylamide, N-propyl acrylamide, N-methyl methacrylamide and N-isopropylmethacrylamide and N-vinyl pyrrolidone. Also polymers of the alkylacrylates and methacrylates with 30-50% of hydroxyethyl and hydroxypropyl acrylates and methacrylates are included in this less preferredcategory.

In addition to the monomer and monomer mixtures set forth above toprepare polymers there can be added to the monomer or monomer mixture upto 15% by weight of the total monomers of acrylic acid, methacrylicacid, itaconic acid, maleic acid or fumaric acid.

While in Shepherd patent 3,428,043 there is described the use of abandage comprising a fabric having an infrequently cross-linkedhydrophilic polymer combined therewith the polymers of the presentinvention unlike those set forth in the Shepherd patent aresubstantially devoid of cross-linking. Thus while the slight amount ofcrosslinking ethylene glycol dimethacrylate impurity (about 0.1 to 0.2%normally present in hydroxyethyl methacrylate can be tolerated anycross-linking agent present should not be sufiicient to interfere withcompatibility of the hydrophilic polymer with the plasticizer-solvent soas to prevent plastisol formation or otherwise interfere with theformation of the bandage on the wound.

The presently most preferred polymer is Hydron S, a commerciallyavailable polymer of hydroxyethyl methacrylate. It is essentially ahomopolymer except for the presence of a trace (about 0.1% by weight) ofethylene glycol dimethacrylates.

The main requirements of the polymers useful in the present inventionare:

(1) Non-tackiness.

(2) Sufficient hydrophilic character to possess moisture vaporpermeability of at least 200 grams/sq. meter/ 24 hours/mil, preferablyat least 500 grams/sq. meter/24 hours/mil.

(3) Susceptibility to solvation (plastisol formation) by the usefulpolar plasticizer-solvents.

(4) Insolubility in water.

(5) Sufficient friability to be able to be prepared as a finely dividedpowder, e.g. less than 100 mesh and preferably less than 200 mesh (TylerScreen series).

Plasticizer-solvents useful for film formation in combination with thepolymer-powders include water soluble polar compounds including glycolssuch as propylene glycol, ethylene glycol, trimethylene glycol,butanediol-1,3, butanediol-l,4, hexanediol-2,5,2-methyl-2,4-pentanediol, heptanediol-2,4, 2-ethyl-1,3-hexanediol,diethylene glycol, triethylene glycol, tetraethylene glycols and otherpolyethylene glycols having a molecular weight up to 800 (e.g. hydroxyterminated polymers of ethylene oxide having average molecular weightsof 200 800), dipropylene glycol, tripropylene glycol and otherpolypropylene glycols having molecular weights up to 900, propyleneglycol nionoethyl ether, mono acetin, trl(hydroxyethyl) citrate,

di(hydroxypropyl) oxalate, hydroxypropyl acetate, glyceryl triacetate,glyceryl tributyrate, liquid sorbitolethylene oxide adducts, liquidglycerine-ethylene oxide adducts, diethylene glycol monomethyl ether,diethylene glycol monoethyl ether, ethylene glycol diacetate.

The ratio of the plasticizer-solvent to the polymer is not particularlycritical and satisfactory results are obtained in the range of from%-20% polymer to 20%- 80% plasticizer-solvent, more preferably 3070%polymer to 70-30% plasticizer-solvent.

Unless otherwise indicated, all parts and percentages are by weight.

In practice, it has been found that a light application of theplasticizer-solvent to the skin followed by application of the polymerpowder results in adherence of a sufficient quantity of the powder tothe area wet with the plasticizer-solvent to result in a strong, tough,adherent film. The film can be built up to any desired thickness but isusually about 10 mils.

The spray-on bandage of this invention is most conveniently appliedusing aerosol spray techniques although a layer of liquid followed by alayer of polymer can be applied by brushing, dabbing, etc. The bandagemay be applied by a Z-separate spray technique wherein theplasticizer-solvent is first applied, followed by application of thepowder from a separate container. Alternatively, the powder and liquidmay be applied simultaneously from separate aerosol cans and valveswhich have a common activating mechanism. In some cases the powder andliquid may be applied from the same can in which case, the presence ofthe propellant in the can prevents solvation and agglomeration of thepowder by the plasticizer solvent.

Suitable propellants include those well known in the art. There can beused compressed gases such as carbon dioxide, nitrous oxide, nitrogen,liquified volatile hydrocarbons such as propane, n-butane, isobutane and2-methyl butane, methylene chloride, vinyl chloride, fluorinatedcompounds including perhalogenated compounds and fluorinatedhydrocarbons such as dichlorodifiuoromethane (Freon l2),trichlorofluoromethane, 1,2-dichlorotetrafluoroethane,octofiuorocyclobutane, chlorodifiuoromethane, 1,1-difluoroethane, vinylfluoride, vinylidene fluoride, l-chloro-l,t-difluoroethane. Thepropellant should contain a substantial amount of volatile materialboiling at not over 20 C., but there can also be present a significantamount of less volatile material boiling up to 50 C.

The invention will be understood best in connection with the drawingswherein:

FIG. 1 is a perspective view illustrating the spraying of theplasticizer-solvent according to the invention;

FIG. 2 is a perspective view showing the spraying of the polymer;

FIG. 3 is a view of the finishing bandage; and

FIG. 4 is a view of an alternative method according to the invention.

Referring more specifically to FIGS. 1 and 2 of the drawings there isshown a skin area 2, e.g. on the arm, having a cut 4 thereon. Fromaerosol can 6, there is directed a spray 8 of appropriateplasticizer-solvent, e.g. propylene glycol by means of propellant, e.g.dichlorodifluoromethane. After the spraying of the plasticizer-solventis completed, there is then sprayed from aerosol can 10 powdered HydronS 12 on top of the plasticizer solvent. The Hydron S merges with theplasticizer-solvent to form the completed bandage 14 as a plastisol asshown in FIG. 3.

In the form of the invention illustrated in FIG. 4 a single aerosol can16 is provided with a chamber 18 for the Hydron S and a separate chamber20 for the propylene glycol plasticizer-solvent. When valve 22 isoperated in the direction of the arrow, it releases the polymer 18 andplasticizensolvent together with the propellant as shown to coat thewound 24 on skin 26 to provide a bandage.

Example 1 This example illustrates the use of a technique of forming aspray-on bandage which does not possess all of the advantages of theinvention.

Into a 6 ounce aerosol can was charged 10 grams of a 10% solid solutionof Hydron S in 45 grams of 95% ethanol and 20 grams of methylenechloride. The can was sealed with a valve and 25 cc. of Freon 12 wereadded as the propellant. The resulting spray placed a good film upon theskin surface but was objectionable because of inherent sting responsewhen applied to the wound. Replacement of a portion of the ethanol withwater did not appreciably decrease the sting.

POWDER SPRAYS Example 2 In this example a two can system was employed.

Component A was made by charging a six ounce aerosol can with 20 gramsof propylene glycol, sealing with a dispensing valve and thenadditionally charging with 80 cc. of Freon 12.

Component B was made by charging a six ounce aerosol can with 10 gramsof Hydron S powder (270 to 325 mesh, Tyler sieve), sealing with a powdervalve and further charging with a mixture of 10 grams of methylenechloride and 20 cc. of Freon 12.

For use, a light coat of Component A (liquid) was sprayed upon skin,e.g. a hand having a cut therein, leaving a wet film. The wet film wasthen oversprayed with Component B (powder) until the skin area was whiteand slightly dusty. Within 10-30 seconds the powder and liquid coalescedto form a flexible protective skin coating which was readily removableafter soaking the hand in water.

In Examples 3-6 a one can system was employed.

Example 3 A single, two chambered aerosol can assembly was utilized inconjunction with a conventional codispensing valve assembly. Filling wasas follows:

A six ounce aerosol can was charged with 10 grams of Hydron S powder,220 to 325 mesh, and sealed with a co-dispensing valve and bag assembly.The bag chamber was then charged with a mixture of 8 grams of propyleneglycol and 32 grams of Freon 12. Depression of the valve button thencodispersed powder and liquid which formed a skin covering over a wound,e.g. on the hand.

Example 4 To alter humectant, physical and adhesive properties of thefinal spray-on bandage other coalescent solvents can be used incombination with or in replacement of propylene glycol. Numeroussolvents of this type are set forth above. Among the preferred solventsof this type are glycerine, polyethylene glycol, monoacetin andtriacetin.

A six ounce aerosol can was charged with 10 grams of Hydron S powder,270 to 325 mesh and sealed with a codispensing valve and bag assembly.The bag chamber was then charged with a mixture of 4 grams of glycerine,4 grams of propylene glycol and 32 grams of Freon 12. The resultingbandage showed increased humectant properties and good adhesion to theskin surrounding a wound, eg on a leg.

Example 5 The procedure of Example 4 was repeated replacing thepropylene glycol by 4 grams of polyethylene glycol 200 (polyethyleneglycol having an average molecular weight of about 200) to obtain abandage on the skin over and around the wound.

Example 6 The procedure of Example 4 was repeated replacing thepropylene glycol by 4 grams of triacetin to obtain a satisfactorybandage over the wound.

Example 7 The procedure of Example 2 was repeated replacing thepropylene glycol by polyethylene glycol 200 to obtain a satisfactorybandage.

Example 8 As previously pointed out in place of Hydron S other linearcopolymers can be used. The term copolymers is intended to includepolymers of two or more copolymerizable materials, i.e. it is generic toterpolymers, tetrapolymers, etc. These copolymers can be prepared asstated from combinations of hydroxyethyl methacrylate mono mer with themonomers of hydroxypropyl methacrylate, methoxyethyl methacrylate,ethoxyethyl methacrylate, methyl methacrylate, ethyl methacrylate, butylmethacrylate, hydroxyethyl acrylate, hydroxypropyl acrylate, butylacrylate, t-butylaminoethyl methacrylate, diethylaminoethylrnethacrylate, methacrylic acid, acrylic acid, itaconic acid, diacetoneacrylamide, etc.

A copolymer prepared from 50% hydroxyethyl methacrylate and 50% methylmethacrylate was pulverized to 270 to 325 mesh, 10 grams of the powdercharged into a six ounce aerosol can and sealed with a codispensingvalve and bag assembly. The bag chamber was charged with a mixture of 4grams of propylene glycol, 4 grams of triacetin and 32 grams of Freon12. The resulting spray gave a skin coating around a wound similar tothose set forth in Examples 2-7.

Example 8 was repeated using a terpolymer of 50% hydroxypropylmethacrylate, 10% methacrylic acid and 40% diacetone acrylamide withsimilar results.

Furthermore medicinally active ingredients such as germicides,fungicides, antibiotics, steroids, local anesthetics or the like may beutilized by having the medicinally active ingredient suspended orentrapped in the polymer, or if desired dissolved in the liquid phase ofthe system. Examples of such medicinally active ingredients includebenzocaine, xylocaine, aspirin, sodium omadine (a derivative of1-hydroxypyridine-Z-thione), hexachlorophene, bacitracin, cortisone,trimethyl benzyl ammonium chloride, cetyl pyridinium chloride,penicillin, Aureomycin (chlorotetracycline), chlorornycetin(chloromphenicol), merthiolate, sulfanilamide, sulfathiaozole,sulfaguanidine, sulfapyridine, salicylic acid, Griseofulvin, undecylenicacid, zinc undecylenate, tetracycline, hydroxytetracycline (Terramycin),dienestrol, ethynyl estradiol, diethyl stilbesterol, estradiol,myltestosterone, progesterone, ascorbic acid.

SUSPENSION OF MEDICALLY ACTIVE INGREDIENTS Example 9 To illustrate useof the invention with a fungicide, a six ounce aerosol can was chargedwith 9.98 grams of Hydron S powder, 270 to 325 mesh in which wasdispersed 0.02 gram of sodium omadine. The can was sealed with aco-dispensing valve and bag assembly. The bag chamber was then chargedwith a mixture of 8 grams of polyethylene glycol 300 (polyethyleneglycol having an average molecular weight of about 300) and 32 grams ofFreon 12. The resulting film formed by spraying upon a colony of fungus(Aspergillus niger) showed marked depression of colony growth. Theformulation was also sprayed on the skin around a wound to form abandage.

Example 10 Example 9 was repeated using 9.7 grams of a 50-50 copolymerof hydroxypropyl methacrylate with methoxyethyl methacrylate and having0.3 gram of hexachlorophene (a germicide) dispersed throughout thefinely divided copolymer. The resulting film showed good suppressionupon a colony of Salmonella typhosa. A spray on bandage was alsoprepared over a wound on the scalp.

Example 11 The procedure of Example 10 was repeated replacing thehexachlorophene by 0.3 gram of Bacitracin (or antiseptic). The filmformed on spraying showed good suppression upon a colony growth ofstreptococci. A spray on bandage was also produced on skin on the cheek.

Example 12 The procedure of Example 10 was repeated replacing thehexachlorophene by 0.3 gram of cortisone. When the spray on bandage wasformed on the skin good antiinflarnmatory effect upon the skin wasnoted.

Example 13 The procedure of Example 10 was repeated using 0.3 gram ofBenzocaine (ethyl aminobenzoate, a local anesthetic) in place of thehexachlorophene. The resulting film showed good pain suppressingqualities upon abraded skin.

Example 14 Any medically active ingredient that is soluble in ethanol oran ethanol-water mixture can be put into solution with Hydron S or otherhydroxyethyl or hydroxypropyl methacrylate polymers. Such solutions arethen dried to a solid by any method known to the art, e.g. tray drying,roller drying, vacuum drying, spray drying, and then reduced tosprayable power form to produce an entrapped medically activeingredient.

For example, 9.0 grams of Hydron S plus 1 gram of Benzocaine weredissolved in 30 cc. of 95% ethanol. The solution was vacuum dried andthe resulting polymer mix was pulverized to 270 to 325 mesh. Thispolymer mix was charged into an aerosol can as described in Examples land 13. Upon spraying to form a bandage, the final film produced on theskin showed the same pain suppressing qualities as in Example 13 above.

Example 15 If the medically active ingredient is soluble in the liquidphase of the system, it can be dissolved in that phase with resultssimilar to those described in Examples 9-14.

For example a six ounce aerosol can was charged with 9.7 grams of HydronS, 220 to -325 mesh and sealed with a codispensing valve and bagassembly. The bag chamber was then charged with a solution of 8 grams ofpropylene glycol containing 0.3 gram of hexachlorophene and 32 grams ofFreon 12. The sprayed film produced the same suppression of a Salmonellatyposa colony as in Example 10. A satisfactory spray-on bandage was alsoproduced on skin having a wound therein.

Obviously the medicinally active ingredient can be added to both thepolymer and the plastisol forming solvent or plasticizer.

What is claimed is:

1. In a method of forming a powdery bandage in situ on skin having awound therein which is readily removable therefrom after soaking, theimprovement comprising the steps of (a) applying, as a powder, ahydrophilic water insoluble hydroxy or lower alkoxy lower alkyl acrylateor methacrylate polymer or a copolymer of 20 to 70% of a lower acrylateor methacrylate and 80 to 30% of acrylamide, methacrylamide, N-loweralkyl acrylamide or methacrylamide, or N-vinylpyrrolidone as a powderand (b) applying, simultaneously or in succession, a high boiling liquidplasticizer or solvent therefor which does not cause a burning orstinging sensation when applied on the skin and wound to form aplastisol film on the skin resulting from adherence of the powder to thewound area wet with the non-stinging plasticizer-solvent therebycovering said wound wherein the polymer powder and plasticizer aresprayed from separate containers in succession, or wherein the polymerpowder and plasticizer are simultaneously sprayed from separate chambersin a single container, or wherein the polymer powder and plasticizer aresprayed simultaneously from the same chamber in a single container, theplasticizer and polymer powder being kept separate by the propellantwhich prevents solvation and agglomeration of the polymer powder by theplasticizer.

2. A method according to claim 1 wherein the polymer is in finelydivided form substantially uncrosslinked and has a moisture vaporpermeability of at least 200 grams/ sq. meter/24 hours/mil and theapplication is accomplished by spraying as an aerosol with the aid of apropellant.

3. A method according to claim 2 wherein the polymer has a moisturevapor permeability of at least 500 grams/ sq. meter/24 hours/mil.

4. A method according to claim 2 wherein there is included an effectiveamount of a medicinally active antiseptic germicide fungicide orantibiotic, local anaesthetic and/or anti-inflammatory steroidingredient in at least one of said polymer and said plasticizer, saidincorporated medically active ingredients diffusing from the film to thewound area over extended periods of time, thereby keeping the wound areafree from infection, infiammation, or providing local anesthesia oranalgesia.

5. A method according to claim 2 wherein the polymer powder andplasticizer are sprayed from separate containers in succession.

6. A method according to claim 2 wherein the polymer and plasticizer aresimultaneously sprayed from separate chambers in a single container.

7. A method according to claim 2 wherein the polymer powder andplasticizer are sprayed simultaneously from the same chamber in a singlecontainer, the plasticizer and polymer powder being kept separate by thepropellant which prevents solvation and agglomeration of the polymerpowder by the plasticizer prior to spraying.

8. A method according to claim 2 wherein the polymer is selected fromthe group consisting of polymers of hydroxy lower alkyl acrylates,hydroxy lower alkyl methacrylates.

9. A method according to claim 8 wherein the lower alkyl group has 2 to3 carbon atoms.

10. A method according to claim 9 wherein the polymer is essentially ahomopolymer of hydroxyethyl methacrylate.

11. A method according to claim 9 wherein the polymer is a copolymer ofthe hydroxy lower alkyl acrylate or methacrylate with each other or withup to 50% of a lower alkyl acrylate or methacrylate, a hydroxy loweralkoxy lower alkyl acrylate or methacrylate, acrylamide,methacrylarnide, N-lower alkyl acrylamides and methacrylamides, loweralkoxy lower alkyl acrylates and methacrylates, diacetone acrylamide,diacetone methacrylamide, N-vinyl pyrrolidone or polymerizable aminosubstituted mono ethylenically unsaturated monomer.

12. A method according to claim 11 wherein the hydroxy lower alkylacrylate or methacrylate is hydroxyethyl methacrylate.

13. A method according to claim 11 wherein there is also included in thepolymerizable monomers an unsubstituted ethylenically unsaturatedcarboxylic acid in an amount up to 15%.

14. A method according to claim 9 wherein there is also included in thepolymerizable monomers an ethylenically unsaturated carboxylic acid inan amount up to 15% 15. A method according to claim 14 wherein the acidis selected from the group consisting of acrylic acid, methacrylic acid,maleic acid, fumaric acid and itaconic acid.

16. A method according to claim 2 wherein the polymer is a copolymer of20 to 70% of a lower alkyl acrylate or methacrylate and to 30% of alower alkoxy lower alkyl acrylate or methacrylate, acrylamide,methacrylamide, N-lower alkyl acrylamides and methacrylamides, orN-vinyl pyrrolidone.

17. A method according to claim 1 wherein the bandage has a thickness ofabout 10 mils.

References Cited UNITED STATES PATENTS Brown et a]. 424-81 Leader 424-81Gallienne et al. 424-81 Wichterle et a] 18-58 Maeder 424-81 Wichterle eta1. 18-58 10 3,269,903 8/1966 Van Fieandt et a1. 424-81 3,400,890 9/1968Gould 239-36 3,428,043 2/1969 Shepherd 128-268 3,483,870 12/1969 Cooveret a1 128-334 5 SHEP K. ROSE, Primary Examiner US. Cl. X.R.

424-28, 32, 33, 45, 7s, 80, 81; 12s s2, 114, 155, 156, 172, 260,265,268, 334, 335.5

